Sheet of abrasive material



March 25,1941. B. F. WINSLOW u SHEET 0F ABRASIVE MATERIAL Filed May 15, 1959 Fig] L Patented Mar. 25, 1941 UNITED STATES snus'r or ammsrve MATERIAL Bulkeley l". Winslow, Broolilinc, Mass, assignor to United Shoe Machinery Corporation, Borough oi Flcminzton, N. 41., a corporation of New Jersey Application May l5, 1939, Serlalhlo. 213,733

d Glaims.

This invention relates to sheets of abrasive material prepared in such manner that. they may be shipped to the user and readily applied by him to their intended use. While the invention is it illustrated with reference to abrasive sheets intended as the work treating elements of bumng rolls commonly employed in shoe and leather worlr, it is to be understood that the sheets may m be applied to other rolls and for other purposes.

abrasive sheet material ready for instant application to builing rolls without the necessity oi providing any securing means other than that carried by each sheet of such material. lit is a lurther object of the invention to provide adhesive layers along end margins upon opposite sur- :laces of each sheet of a character such that such end margins will instantly be bonded together merely by pressure, thus reducing to a minimum the time and eflort necessary to secure the abraslve material in place on a bumng roll. l 'urther objects of the invention are to provide an abrasive sheet that will be ready tor operation the instant it has been secured in place on a roll, by pressure upon such adhesive-carrying marginal portions of the sheet, and further to provide a joint which will be strong enough to maintain till the abrasive sheet in position and in perfect condltion for its intended use and at the same time flexible, thus minimizing any tendency to a hard resistant area at the location of said joint.

To these ends, and in accordance with an important feature of the invention, a quadrilateral sheet of abrasive material is provided along opposite marginal portions and on opposite sides oi the sheet with layers of adhesive material covered by protective strips readily removable to uncover tacky surfaces on the adhesive layers which need no activation but which will firmly adhere to each other instantly upon suitable pressure,

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thereby facilitating the application oi the abrasive sheet material to a roll or other cylinder suitable for buffing, sanding or scouring purposes. in a preferred form of the invention, a sheet of paper having a surlace layer of abrasive material on one side only is provided along an abrasive marginal portion thereof with a layer of rubber cement of a consistency to fill in the abrasive surface of such marginal portion of the sheet and to effect a strong bond with such surface, said sheet having also a layer of rubber cement applied to the plain surface of the sheet along a marginal portion opposite to the first-mentioned marginal portion. Subsequently both cement layers are covered by a layer of latex-which is It is an object of the invention to provide or n-no) allowed to dry for a suitable time, the latex layers being then covered by protective strips of suitable material, such as Cellophane, the latter serving to protect the tacky surface of the later: and lseep it in good condition so that the latex layers will instantly become bonded to each other upon being superposed and subjected to pressure. This abrasive sheet with its protected, pressureresponsive layers of adhesive constitutes an ar ticle of manufacture a plurality of which may be readily stacked and packaged for shipment, since the adhesive-carrying edges are protected or masked so that there will be no adhesion between adjacent sheets in the stack.

Othcradvantages of the described article reside in the fact that each sheet is ready for instant application to its intended use simply by removing the protective strips from the marginal portions of the sheet just before such marginal portions are brought into contact with each other. Since the adhesive layers need no activation by solvent or by heat or otherwise, such adhesive portions may be instantly united simply by pressure and'the roll thus provided with an abrasive covering may be immediately put into operation. Because of the strong bonding union between the overlapped and underlapped marginal portlons of the abrasive sheet, no other means is needed to hold the abrasive covering on the bulllng roll. Hence, the latter may present a smooth unbroken surface in sharp contrast to bumng rolls heretofore commonly provided lor commercial purposes, particularly for operations upon shoes and tanned hides and skins.

With these and other objects and advantages in view the invention will now be described in detail in the specification and then pointed out more particularly in the appended claims.

in thedrawlng, i

Fig. l is a plan view of a quadrilateral sheet of abrasive paper having protected layers of pressure-responsive adhesive applied to opposite marginal portions of the sheet on opposite sides thereof;

Fig. 2 is an enlarged sectional view taken along the line Ill-ll oi Fig. l, the view being schematic, not actual;

Fig. 3 is a package of sheets, each of the construction shown in Fig. l; and

Fig. 4 is a rubber-covered roll having a sheet of abrasive paper secured in place on the cylindrical surface of the roll by having its adhesivecarrying edges lapped and pressed together.

In the illustrated article, which is specially designed for use on buffing rolls, there is shown a lid till

rectangular sheet of paper 10 having a suitable abrasive material H uniformly disposed over one side thereof, the other side of the sheet being plain and even, since it is to contact the cylindrical surface of a roll I2 suitable for buffing, sanding or scouring operations. Applied to a marginal portion ll of the abrasive surface is a layer of rubber cement IS, the cement being of a consistency and of sufflcient quantity to fill in substantially the abrasive surface and provide a practically even surface, in spite of the fact that the abrasive material over the surface of the sheet presents an uneven surface with spaces between upstanding abrasive particles designed to abrade a work piece. After the rubber cement has dried sufficiently, the time required being two or three minutes in a heated chamber, a. layer I8 of latex is applied over the rubber cement layer I6, the latex further filling in any low spot left unfilled by the cement. This latex layer is allowed to dry about the same length of time as the rubber cement layer to provide a tacky surface which is then promptly covered by a protective strip 2a of a suitable material, such as Cellophane, which will not adhere too strongly to the latex surface. Similar layers of rubber cement and of latex are applied in the order described to the opposite marginal portion 22 of the sheet i and to the opposite side of the sheet, that is, to the plain surface, as distinguished from the abrasive-carrying surface. Any slight inequalities which may remain on the margin M, after the application of the cement and latex layers, as when an exceptionally coarse abrasive material is employed, become embedded later in the latex and cement layers on the plain-surfaced margin 22 when the adhesive-carrying margins 14 and 22 are bonded together, as will be readily understood. Subsequently a strip of Cellophane 20 is applied over the latex layer on the marginal portion 22 of the sheet. Since the abrasive sheet material, when thus prepared, has its adhesivecarrying edges protected by strips of Cellophane, there is provided an article a number of which may be packaged in a stack of any suitable size preliminarily to distribution to users of bumng, sanding or scouring machines.

In providing an adhesive for securing together opposite marginal portions 'of a sheet of abrasive material, I have utilized a rubber cement which forms an excellent bond with both the plain paper surface and with the abrasive surface, in the lat ter case also filling in the spaces between the abrasive particles to make a substantially even surface to which the protective strip will adhere with sufficient firmness so as not to be prematurely displaced therefrom. While any suitable rubber cement may be used, I have found that a rubber cement which contains rosin and reclaimed rubber gives excellent results. The rubber cement not only makes a better bond with the paper but it has no disadvantageouseifect thereon, whereas, the latex, if applied directly to the paper, would wet the latter with the result that wrinkles would subsequently be formed in the paper. By applying a layer of latex to the properly d1 red rubber cement layer, and allowing the latex to dry for-a suitable period, there is provided a pressure-responsive adhesive layer (completely bonded with the rubber cement) that needs no activation. Incidentally, many adhesives need the application of heat or of a solvent to be properly activated when the time comes .for eifei tive union with a similar layer of ad- The strip of Cellophane has been found to adhere sufliciently to the latex layer to insure against premature displacement, while at the same time it may be readily stripped from the latex surface when the bonding of the two latex surfaces is to take place.

Preferably, the abrasive sheet material will be applied to a roll l2 (Fig. 4) having a layer of rubber 24 cemented to the surface of a metal roll 25, the meeting edges of the rubber layer being indicated by the dotted line 26. It is to be understood, of course, that the rubber layer may be secured to the metal cylinder by any other wellknown means.

In order to apply an abrasive sheet like that shown at it] to the cylindrical surface of the roll 52, the sheet is wrapped around the roll with the abrasive-carrying surface on the outside. With the sheet in the desired position the strips of Cellophane are readily peeled from the marginal portions to be lapped, the margin 22 being the overlapping margin, and manual pressure is applied along the length of said lapped marginal portions. When the marginal portions H and 22 have been properly applied to each other, and a bond formed in the adhesive layers through the pressure applied to said marginal portions, the abrasive covering is not only secured in place on the bufllng roll but it is ready without delay for efifective work as an abrasive. The initial bond thus obtained is adequate to hold the lapped margins from separating under the usual working conditions, it being pointed out that, even if the lapping of the adhesive margins and the applying of manual pressure thereto be carelessly and hastily performed, the bondis perfected by the pressure of the work piece held in engagement with the abrasive surface while the tool is rotated. It will be found that the Joint thus formed between the overlapping marginal portions of the abrasive cover is permanent, at least, from the standpoint of its intended service. Furthermore, the joint thus formed by pressure-responsive adhesive is a flexible one, thus minimizing the effect of thickness due to overlapping layers of sheet material and of adhesive at the location of the joint. When it is desired to remove this abrasive sheet at the end of its effectiveness as an abrasive on the bufling roll, it is necessary only to slit the paper at a suitable point, for instance, along the dotted line 26 where the edges of the rubber layer come together, or to tear the paper oil the roll. whereupon a new abrasive cover may be applied in the manner already described.

The abrasiv sheets III will be sold in suitable packages such as that shown at 30 in Fig. 3, wherein a stack of twenty-five sheets are shown held in packaged form by a, binder 32 which may be readily cut or broken to release the sheets III for use.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

1. An article of manufacture comprising a sheet of material having an abrasive coating upon one of its surfaces and having its end margins upon opposite surfaces of the sheet provided with a layer of pressure-responsive adhesive maiteriai to enable said end margins to be joined in lapped relation, said adhesive material covering the grainsof abrasive material and substantially filling the spaces between them, said adheslve material also having flexible and resilient properties to'contribute to the making of a yieldable joint without requiring removal of the abrasive coating at the joint.

2. An article 01' manufacture comprising esheet of materialhevingasin-Iecelayerotebrasive materialononeside'onlyandhavinzifurthera layeroirubber cement appliedtonmeraimlpqr- 'tionottheabmsivesurtaceotthesheettocqver thegminsorabmsivenmterialand fill the spaces between them'snd having 9.50 a rubbercement layer appiiedtoanoppositemargiml portion and on the plan-1mm.- of the sheet, said sheet having further a layer of latex' applied over each rubber cement layer, whereby the adhesivewrying marginal portions oi the sheet may be instantly united, when pmperly superposed, merely by pressure to secure aenrm bond betwcen'such supeipdscd ofthe sheettosecurethelatterin piaceonarpll or other buiiing tool, the rubber and latex layers being flexible and resilient and thus ccnmbutins tothemakingofayieldabieiointintheoverlapped portions of the abusive meet despite the presence of abrasive material in the joint.

imposing thereon at reverse sides of an ebrasiveiy coated sheet 10 strongly adhesive to each other in response to pressme, which consists iii first applyin to said margins a. coating of rubher cement, the coating on the abrasive side of the sheet being sumcient to fill in the irneg'ulnrities oi the abmslve sur- 15 face to provide a substantially even surface of cement, and then, after the cement has set. superg, e-responsive costin BUIKELEY r. wmsnow; 2o 

